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updates to "Malt Inoculated Wort"
====Malt Inoculated Wort====
In 2016 and 2017, Dr. Matt Bochman or Indiana University and Jeff Young of Blue Owl Brewing conducted an experiment to map the microbiome of wort that was inoculated with several years and harvests of malted barley. Using DNA sequencing, they analyzed analysed the microbes present in 110°F wort that was inoculated with crushed malted barley at 0 hours, 24 hours, and 48 hours. The 7 malted grains that used to inoculate the wort were 2015 Breiss Merit 57, 2016 Breiss Merit 57, 2015 Patagonia Sebastien, 2015 Briess Copeland, 2016 Blacklands Endeavor, 2016 Breiss Synergy, and 2016 Weyermann Barke.
The grain samples before inoculation hosted a large variety of microbes, but immediately after inoculating the malted grains into 110°F wort, all of the grain samples were dominated by ''Weissela cibaria'' (ranging from 92-99% across all samples), a Gram-positive bacteria that is in the same order but a different family as ''Lactobacillus''. All but one of the grain samples also had a much smaller but not insignificant population of ''Salmonella bongori'' (1-4% across all samples), which has been associated with non-lethal food poisoning <ref>[https://en.wikipedia.org/wiki/Salmonella_bongori#Pathogenicity_and_epidemiology "Salmonella_bongori". Wikipedia. Retrieved 06/15/2017.]</ref>. There were also trace populations of other bacteria such as ''Enterobacter'' spp., ''Pantoea'' spp., ''Erwinia'' spp., and ''Lactococcus lactis'' in most of the samples. There was a significant ''L. lactics'' population in the 2016 Weyermann Barke, as well as ''Enterobacter aerogenes'' <ref name="blueowl_2017">[https://experiment.com/projects/mapping-the-sour-beer-microbiome/results "Mapping the sour beer microbiome".
After 48 hours, ''Weissella cibaria'' continued to dominate all of the grain samples except the 2016 Breiss Merit 57 (note that the 2015 Breiss Merit 57 was dominated by ''Weisella cibaria''). Two samples, the 2015 Breiss Merit 57 and the 2016 Blacklands Endeavor, also saw an increase in the population of ''Shiggela sonnei'' (2.5%). The ''Salmonella bongori'' was still present in samples after 48 hours, but decreased to less than 1% <ref name="blueowl_2017" />.
Some of the organic acids and alcohols were also measured in this study. Most of the samples created fairly high and similar levels of lactic acid, followed by a smaller amount of acetic acid, and then followed by trace amounts of citric, pyruvic, malic, and succinic acids. The 2016 Breiss Synergy had much more lactic acid, acetic acid, and noticably more succinic acid the all the other samples. It also had considerably more ethanol produced, indicating that wild yeast may have fermented this sample <ref name="blueowl_2017" />. [[Butyric Acid]] and [[Isovaleric Acid]] were not measured due to the difficulty in measuring these acids at the lab that was used <ref>[https://www.facebook.com/groups/MilkTheFunk/permalink/1660708117290729/?comment_id=1661783767183164&reply_comment_id=1664682886893252&comment_tracking=%7B%22tn%22%3A%22R2%22%7D Edwards, John. Milk The Funk facebook group. 04/24/2017.]</ref>. The study concluded that using grain to inoculate wort could potentially be done so in a controlled manner, producing predictable and consistent results. It was stated that more studies need to be conducted to explore the vraiability in brewing process such as temperature and incubation times. For example, while the ''Weisella cibaria'' dominated at 110°F, it is reported that it doesn't tolerate temperatures above 113°F <ref name="blueowl_2017" />. Various concerns on possible cross contamination associated with the methodology of the referenced study by Bochman and Young have been discussed on [https://www.facebook.com/groups/MilkTheFunk/permalink/1660708117290729/ this MTF thread]. See also:* [https://experiment.com/projects/mapping-the-sour-beer-microbiome/results "Mapping the sour beer microbiome" by Matthew Bochman and Jeff Young.]* [https://www.facebook.com/groups/MilkTheFunk/1722624404432433/ ASBC presentation by Jeff Young.]
==Miscellaneous==